High value items, such as wristwatches and value documents, have always been at risk of counterfeiting. A variety of technologies, sometimes exotic, and expensive, have been developed to combat such crimes.
Counterfeiting has more recently extended into more mundane items. Items that are now widely counterfeited include a variety of foodstuffs and pharmaceuticals. The economics of anti-counterfeiting technologies developed for high value items sometime preclude their use with inexpensive items.
Digital watermarking is used in certain embodiments of the present technology. As is familiar, digital watermarking is used to steganographically mark objects with information (commonly a plural-bit payload) in a manner that permits computer recovery of the information, yet escapes human attention.
In accordance with one aspect of the presently-described technology, material processing that is conventionally employed in manufacturing packaging for pharmaceuticals and foodstuffs, is adapted to provide an inexpensive anti-counterfeiting technology. While inexpensive, the present technology can also serve as a further layer of security for use with high value items.
In one particular embodiment, a substrate (e.g., foil) is ink-printed (or otherwise-printed) with product markings in a conventional manner. The printing (e.g., artwork) is encoded to convey a steganographic digital watermark. This watermark conveys a plural-bit payload, but lacks a spatial calibration signal that is normally included.
The missing spatial calibration signal is provided by an embossing operation, e.g., using a pressure roller. (Foil packaging is often embossed with a fine pattern to improve its aesthetics, and to aid in its machine- and human-handling.)
Since the payload and calibration signal components are applied in different operations, there is typically an unknown spatial offset between their placements on the substrate. That is, they are not perfectly aligned. This offset is sensed following production of the substrate, and corresponding information is stored in a reference database—commonly in association with the watermark payload.
When a suspect product is later found in a retail setting, it can be checked to determine whether the payload and calibration signals are spatially offset in the manner expected (and indicated in the reference database). If not, the product is flagged as counterfeit.
One particular example of such technology is in producing foil or plastic lids for retail yogurt cups. A multitude of yogurt lids are cut from a single roll of such processed substrate. Each lid in the production run is characterized by the same offset between watermarks.
In accordance with a second aspect of the presently-described technology, a substrate is again processed to form plural patterns that are spatially-offset. In this second aspect, however, an offset between two of the patterns is made to vary over the length of the substrate. This variation effects serialization of different portions of the substrate (e.g., serialization between lids, in the just-mentioned yogurt example). Such serialization can serve a variety of advantageous purposes.
A bit of further background: Years ago, it was commonplace for cereal companies to offer prizes for consumers who mailed in five or ten cereal box-tops. (Today there are still fundraisers that involve consumers collecting boxtops, and mailing them in (e.g., to Box Tops for Education) to earn a dime contribution to a designated school or charity.)
Similarly, there have been retail promotions in which the consumer's purchase of a specially-marked product wins the consumer a prize. (Pepsi famously offered a million dollars to the consumer who found a prize-entitling bottle cap. The plot of the Willy Wonka book/movie revolves around such a promotion, which entitled five winners to a lifetime supply of chocolate.) Related are arrangements in which a consumer scratches-off an obscuring coating from a product or card, to reveal a prize, or to reveal an indicia that can be collected with other such indicia to win a prize.
There are now updated counterparts to these promotions—many employing smartphones to enter codes found on or in packages. Starbucks, for example, offers a $10 gift card to consumers who purchase 4 specially-marked bags of coffee, and enter the “star codes” from the packages on a prize redemption web page. (The codes are revealed when an adhesive sticker is pulled from the package.) Other promotions involve use of a smartphone to scan barcodes/QR codes (or other markings) from eligible products, and receive a reward in return.
To prevent a consumer from earning a reward simply by scanning a single product repeatedly (or entering a single product code repeatedly), different instances of the same product should be differently-marked. Starbucks, for example, prints a different star code on the back of each of the peel-off labels.
Such different marking of different instances of product may be regarded as a form of product serialization. In the past, this has involved considerable effort (as illustrated by the separately printed and applied Starbucks stickers).
Serialization is useful for other purposes as well, including tracking particular instances of product through a supply chain, establishing chain of custody, etc.
In accordance with this second aspect of the presently-described technology, methods and arrangements are detailed to serialize large lots of product at minimal (or no) cost.
As is familiar, digital watermarking can be employed to mark objects with two or more watermarks.
Exemplary is an arrangement shown in applicant's U.S. Pat. No. 6,636,615, in which an object is marked with both a frail and a robust watermark. The former degrades when the object is copied—permitting copies to be distinguished from the original object. The robust watermark persists despite copying.
Philips' U.S. Pat. Nos. 6,505,223, 7,127,065 and 20070165851 teach methods for marking video and other media content, employing two or more watermarks that are spatially offset from one another. The offsets are prescribed by a computer system (or a human operator), and serve to communicate desired payload information. BBC's patent document 2006133647 teaches another arrangement in which watermark patterns are shifted in a controlled manner to convey intended information.
Applicant's patent publication 20130223673 discusses how digitally watermarked packaging of grocery items can be used in games and other promotions, and how the hidden nature of the marking helps defeat shopper gaming of such systems.
One exemplary embodiment of this aspect of the present technology employs a web offset printing press, with plural cylinder-based print mechanisms. These cylinders bear printing plates that apply successive layers of ink, in desired patterns, to a roll of paper or other substrate. A printed web of substrate results, and is thereafter cut into items of product packaging (e.g., yogurt lids, labels, etc.).
A printing plate on one of the cylinders is shaped to apply a first repetitively-tiled watermark, and a printing plate on another cylinder is shaped to apply a second repetitively-tiled watermark. The two watermarks are characterized by different measurements, e.g., tile (block) widths. This causes the spatial offset relationship between the two watermarks to vary at different points along the printed substrate—as the printed watermark blocks overlap in progressively changing manners. This variation yields hundreds or thousands of different watermark spatial offsets, which serve as a form of serialization by which different instances of the same product package can be distinguished.
The number of differently-distinguishable packages formed from such a printed web can be exponentially increased, into the tens- or hundreds-of-thousands, or millions, by encoding different information into each of the watermark blocks formed on the printing plates.
Such a production arrangement employs conventional printing apparatus, and adds no cost to the consumables. Yet it yields vast numbers of separately-distinguishable, but seemingly identical (to humans) items. If a consumer captures three cereal box images (e.g., using a smartphone), the images can be examined to determine the spatial offset (and optionally the payload information) that characterizes the watermark marking of each. This discerned information indicates whether the images depict three different boxes, or a single box that has been photographed three times.
In accordance with yet another aspect of the presently-described technology, the degradation of a marking on an item substrate is used to infer information about the item.
More background: Applicant's publication 20040258274 teaches that laminate constructions, e.g., including epoxy, aluminum, mylar, polycarbonate, polyurethane, Teslin (a synthetic film), and vinyl, can convey digital watermark information. Similarly, publication 20050003297 teaches arrangements for forming digitally-watermarked driver's licenses by marking thermoplastics (such as polyvinylchloride (PVC), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate (PET)), and other materials
Various of applicant's prior publications teach that watermarks can change over time. For example, U.S. Pat. No. 6,332,031 teaches that the energy level of a watermark signal in a banknote diminishes as the banknote becomes worn. Applicant's U.S. Pat. No. 8,181,884 teaches watermarks whose readability change as a function of time, e.g., based on fluorescence or decaying ink. The patent also teaches watermarks that appear or disappear with changes in temperature, e.g., using thermochromatic inks.
Applicant's U.S. Pat. No. 7,537,170 teaches that a printed digital watermark can be covered with a light-sensitive material that gradually becomes darker, with continued exposure to light (e.g., UV or IR). The watermark thus becomes progressively more difficult to read with repeated exposure to light.
Publication 20130088555 notes that security markings can be formed using inks that fade over time—making them suited for perishables or medications that go out of date.
Publication 20120188319 to Xerox details how a photo-sensitive shape-memory polymer can be shaped in a desired pattern by turning the polymer glassy using a first wavelength of light. The process can later be reversed by returning the material to its rubbery state using a second wavelength of light.
Similarly, shape memory polymers can be produced as films, and embossed with covert and overt 3D patterns. The pattern is retained in a fixed state at cooler temperatures, but relaxes back to its unpatterned state over time at higher temperatures. Wikipedia notes that such shape memory films can be used as label substrates or face stock for anti-counterfeiting, brand protection, tamper-evident seals, anti-pilferage seals, etc. Xerox's publication 20120279101 details a variety of shape-memory polymers, and their use as product security labeling.
Guangzhou Manborui Material Technology Co., Ltd, offers security labels for wine and other products employing such memory films. In addition to temperature, transition between patterned shapes can be triggered by electric or magnetic fields, light, or solution. (Guangzhou Manborui's technology is detailed in published PCT patent application WO12040985. Particular application of such technology to an anti-counterfeiting wine bottle cap is shown in published Chinese patent application CN201745882.)
Relatedly, artisans in polymer extrusion are familiar with the phenomenon that if a shaped thermoplastic polymer is cooled before the polymer chains can fully relax, stress can be frozen into the patterned shape. This stress relaxes over time—causing degradation of the shaping.
In one particular embodiment of this further aspect of the technology, a substrate (e.g., a foil or plastic film used in product packaging) is processed to convey both a human-visible structure (e.g., printed artwork), and a steganographically-encoded plural bit watermark payload (e.g., an embossed texture pattern). With the passage of time, the latter pattern degrades (e.g., due to the medium's tendency to return to its original, flat, shape). This degradation leads to raw bit errors when the steganographically-encoded payload is detected and decoded (e.g., by a smartphone). Software in the detection system can use a count of these raw bit errors as an indication of the time that has elapsed since the medium was first embossed. Such technology is useful, e.g., to ensure that foodstuffs and medications are fresh.
In another arrangement, such a film serves as a seal for a container having evacuated or pressurized contents. Under such forces, the substrate is stretched, again leading to distortion of the steganographic pattern, and degradation of the encoded raw bits. Software in the detection system can use a count of resulting raw bit errors to indicate whether the desired pressurization/evacuation has been maintained, or whether the container has reverted to atmospheric pressure.
The foregoing and other features and advantages of the present technology will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.